Behind a Mask of Sugar, a New Battle Front—Targeting Bacteria Associated with Antibiotic Resistance by Spoofing Sugar Signatures
Justin Ragains, associate professor at the LSU Department of Chemistry, recently received $430,960 from the National Institutes of Health to work on a vaccine to prevent infections caused by Acinetobacter baumannii, a species of bacteria associated with antibiotic resistance:

Acinetobacter baumannii
“In a nutshell, this project involves synthetic chemistry to generate vaccines. The
specific bacteria we’re looking at is Acinetobacter baumannii, which is an important pathogen that tends to plague people with traumatic injury
and compromised immune systems, such as patients in intensive care units or soldiers
who’ve just returned with wounds from combat—anyone who’s not 100 percent to begin
with could be vulnerable to this bug. We see more and more strains that are multi-drug
resistant, too, and even some that aren’t susceptible to a single drug on the market.
So, there’s an urgent need for alternatives to antibiotics, and that’s where vaccines
can come to the rescue.
“Our idea is to do something a little bit different than what other people who work
on vaccines have typically done. We’re looking at a specific set of sugars on the
surface of these bacteria called lipooligosaccharides, a molecular signature of sorts.
While the bacteria use these to their own advantage, there’s plenty of evidence that
our immune systems recognize them as antigens, which are substances capable of stimulating
an immune response [triggering the production of antibodies].
“We’re right at the beginning of this three-year project. This is a laborious area
of research, and development of vaccines is something that typically takes years or
decades and a lot of money. So, future funding is something that’s almost certainly
a necessity to keep this work going. Right now, baby steps. Once we’ve synthesized
these antigens, we’ll team up with our very capable collaborators at the LSU School
of Veterinary Medicine and perform a series of biological assays to see whether or
not they hold promise.
“Vaccines based on sugars may seem strange as we’re used to thinking of sugars as
something we metabolize and turn into energy, but sugars are ubiquitous in nature
and serve all kinds of purposes. For example, wood is almost entirely made up of sugars,
and the surfaces of all of the cells in your body and all of the cells elsewhere in
the plant and animal kingdom are covered with them. This sugar coating is very important
for cell-to-cell communication and signaling.
“I would have liked to be the person who came up with the concept of looking at sugars
on the surface of bacteria as immunological targets, but the original work goes back
to the early 20th century. Because of the development of effective antibiotics like
penicillin, however, the idea fell out of vogue. But, since the 1980s or so, the idea
has slowly come back into fashion because people realize that antibiotics alone will
not solve the problems posed by infectious diseases caused by bacteria. When antibiotics
first came, a lot of people thought, ‘So, this problem is solved,’ but as we know
now, it is not.”
Elsa Hahne
LSU Office of Research & Economic Development
225-578-4774
ehahne@lsu.edu